Researchers at the Max Planck Institute for Evolutionary Anthropology inLeipzig, Germany have engineered a mouse whose FOXP2 gene has been swappedout for a different (human) version. This is interesting because the geneis implicated in human language, and this has changed how mice squeak. 'Ina region of the brain called the basal ganglia, known in people to beinvolved in language, the humanized mice grew nerve cells that had a morecomplex structure. Baby mice utter ultrasonic whistles when removed fromtheir mothers. The humanized baby mice, when isolated, made whistles thathad a slightly lower pitch, among other differences, Dr. Enard says. Dr.Enard argues that putting significant human genes into mice is the onlyfeasible way of exploring the essential differences between people andchimps, our closest living relatives.' The academic paper was published inCell.